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testing/running on replica: gets lags via SHOW SLAVE STATUS

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This commit is contained in:
Shlomi Noach 2017-02-02 11:18:07 +02:00
parent 5af70265a3
commit 9d47992d7e
1 changed files with 19 additions and 6 deletions
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25
go/logic/throttler.go
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@ -84,18 +84,30 @@ func (this *Throttler) parseChangelogHeartbeat(heartbeatValue string) (err error
}
}
// collectHeartbeat reads the latest changelog heartbeat value
func (this *Throttler) collectHeartbeat() {
// collectReplicationLag reads the latest changelog heartbeat value
func (this *Throttler) collectReplicationLag() {
ticker := time.Tick(time.Duration(this.migrationContext.HeartbeatIntervalMilliseconds) * time.Millisecond)
for range ticker {
go func() error {
if atomic.LoadInt64(&this.migrationContext.CleanupImminentFlag) > 0 {
return nil
}
if heartbeatValue, err := this.inspector.readChangelogState("heartbeat"); err != nil {
return log.Errore(err)
if this.migrationContext.TestOnReplica || this.migrationContext.MigrateOnReplica {
// when running on replica, the heartbeat injection is also done on the replica.
// This means we will always get a good heartbeat value.
// When runnign on replica, we should instead check the `SHOW SLAVE STATUS` output.
if lag, err := mysql.GetReplicationLag(this.inspector.connectionConfig); err != nil {
return log.Errore(err)
} else {
atomic.StoreInt64(&this.migrationContext.CurrentLag, int64(lag))
}
} else {
this.parseChangelogHeartbeat(heartbeatValue)
if heartbeatValue, err := this.inspector.readChangelogState("heartbeat"); err != nil {
return log.Errore(err)
} else {
this.parseChangelogHeartbeat(heartbeatValue)
}
}
return nil
}()
@ -114,6 +126,7 @@ func (this *Throttler) collectControlReplicasLag() {
readReplicaLag := func(connectionConfig *mysql.ConnectionConfig) (lag time.Duration, err error) {
dbUri := connectionConfig.GetDBUri("information_schema")
var heartbeatValue string
if db, _, err := sqlutils.GetDB(dbUri); err != nil {
return lag, err
@ -272,7 +285,7 @@ func (this *Throttler) collectGeneralThrottleMetrics() error {
// that may affect throttling. There are several components, all running independently,
// that collect such metrics.
func (this *Throttler) initiateThrottlerCollection(firstThrottlingCollected chan<- bool) {
go this.collectHeartbeat()
go this.collectReplicationLag()
go this.collectControlReplicasLag()
go func() {